France 



157 



section), has recently been fitted. Another board of this kind 

 has been ordered for Le Havre from M. Aboilard, the Western 

 Electric Company's agent in Paris. M. Portel Vinay, of Paris, is 

 building a multiple for Bordeaux according to the patents of M. 

 Adhemar. It is said to comprise parallel jacks and indicators 

 which are restored in the act of making a connection, while their 

 coils are automatically cut out, leaving only the ring-off drop in 

 circuit. This is the same idea which has been given effect to in 

 Stockholm and Copenhagen. (See Swedish and Danish sections.) 



At Marseilles there is a multiple designed jointly by MM. 

 Berthon and Ducousso, of which a promised description has not 

 reached the author in time for inclusion in the present work. 



To Lille the Societe Generate des Telephones supplied, some 

 three years back, a multiple on the patent principle of M. Berthon, 

 which presents several points of divergence from ordinary practice. 

 Especially has the inventor aimed at compactness, screening of 

 jacks from dust, and accessibility. The jacks are moulded while the 

 metal is hot in steel dies, so as to insure absolute uniformity. The 

 insulator used is ivorine, a composition which, it is said, possesses- 

 the good qualities of ebonite, combined with greater toughness 

 and workability. The jacks are only 10 mm. thick, which is one 

 millimeter less than the Stockholm Brunkeberg jacks, to be 

 described in the Swedish section. The rows of jacks are very 

 accurately fitted in their frames, and may be pulled out for repairs 

 from the front almost like tiers of drawers. A diagram of the 

 connections is given in fig. 41, and a plan and front view of the 

 jacks and plugs in fig. 42. In this latter, the two wires of the 

 subscriber's loop, or one wire and earth if the system be single, 

 are joined to the springs v v' through the screws z z'. Normally 

 the springs are in contact with studs a a', from which they are 

 lifted by the nose of an inserted plug. The jack sockets are 

 divided into two halves r r', of which r is joined permanently to 

 the studs and r' to the test wire. The plugs are also in two- 

 halves, and shaped to fit into the divided sockets. Referring now 

 to fig. 41, s 1 s- are two subscribers joined to the exchange by the 

 metallic circuits L I L 2 . T T I are two operators' sets with calling 

 keys c and c 1 , which may, as required, direct the current from 

 the battery r through the plug FT. or Fi 2 , and calling keys cz 



